. QST . 2. What causes chirp? Chirp is a change in frequency as the trans-mitter is keyed. There are several possible causesfor the frequency change. One is the voltagechange on the oscillator stage from the key-upcondition to key-down. This can be minimizedby regulating the screen and plate voltages ofthe oscillator stage. Another common cause of chirp is pullingof the oscillator frequency by changing condi-tions in the next stage or stages as the excitationis applied or removed. Changing voltages andcurrents in the stages following the oscillatorreflect a variable load on the oscillator andp
. QST . 2. What causes chirp? Chirp is a change in frequency as the trans-mitter is keyed. There are several possible causesfor the frequency change. One is the voltagechange on the oscillator stage from the key-upcondition to key-down. This can be minimizedby regulating the screen and plate voltages ofthe oscillator stage. Another common cause of chirp is pullingof the oscillator frequency by changing condi-tions in the next stage or stages as the excitationis applied or removed. Changing voltages andcurrents in the stages following the oscillatorreflect a variable load on the oscillator andpull the frequency. When such a condition existsit is necessary to have more or better isolationbetween the oscillator and the changing stage. When persistent cases of chirp are encounteredwith several different crystals, one should lookat the circuit adjustment. An overloaded oscilla-tor can make any crystal chirp. 3. How far can one expect to work with alow-powered transmitter of say 5 or 10 wattsinput?. udw POWER errs out. This is not an easy question to answer becauseof the many variables involved. It will dependa great deal on the location, type of antennaused, frequency, time of day and year, and bandconditions. The condition of the ionosphere, theregion above the earth that reflects radio signals,varies with the time of day, time of year, andthe sunspot cycle. However, it would be safe tostate that with a fair antenna, and exceptionalband conditions, the transmitted signal from a5- or 10-watt station can reach any country inthe world. This holds true for any amateur bandfrom 40 through 10 meters. One amateur using approximately 35 wattsinput worked over 100 different countries on the80-meter band. Many Novices have worked all48 states using very low power. 4. What is the advantage in using the sameantenna for transmitting and receiving? Nearly all antennas will give better perform-ance in certain directions than in others. Toillustrate, lets assume we have a transmittinga
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